Jarring tool



Oct. 22, 968 B. if. ARTEREURY Erm, 3,406,770

JARRING TOOL 5 Sheets-Sheet l Filed June 27, 1966 Oct. 22, 1968 E, RARTERBURY ET AL 3,406,770

JARRING TOOL Oct. 22, 1968 Q P, ARTERBURY ET AL 3,406,770

JARRING TOOL 5 Sheets-Sheet 3 Filed June 27, 1966 United States Patent O3,406,770 .JARRING TOOL Bryant P. Arterbury and Thomas C. Burroughs,Houston, Tex., assignors of thirty-three and one-third percent to Roy L.Arterbury, Houston, Tex.

Filed June 27, 1966, Ser. No. 560,617 8 Claims. (Cl. 175-299) ABSTRACTOF THE DISCLOSURE A well tool adapted to impart jarring impacts to adevice within a well bore, said tool having a tubular body with aninternal projection, a latch body having arms extending through theprojection, a means for preselecting the force at which the latch armspull through the projection, a hammer on the latch body adapted toimpact against one end of the tubular body, means for connecting to thedevice to be jarred and to the surface so that a lifting force may beexerted on the tool to cause it to vbe actuated and to impart itsjarring impact to the device.

The present invention relates to an improved well tool adapted to impartjarring impacts to a device within a well bore.

Jarring tools have been used to jar a well tool or string which is stuckin a well bore to loosen the stuck tool or string and allow itsrecovery. Additionally, jarring tools have been used to set or releaseother well tools within a well bore by the impact which the jarring tooldelivers.

In the uses of such jarring tools, it is often desirable to be able todeliver repeated jarring impacts and particularly to be able to deliverjarring impacts in both an up- Ward and a downward direction.

It is, therefore, an object of the present invention to provide animproved jarring tool to deliver multiple jarring impacts in bothdirections within a well bore.

Another object is to provide an improved well jarring tool which willjar upwardly or downwardly in any sequence desired.

A further object is to provide a well jarring tool for jarring in bothdirections and having a preselected jarring force.

Still another object is to provide a double-acting jarring tool for usein a well bore which may be actuated to jar upwardly or downwardly bymanipulation of the means suspending the tool in the well bore.

A still further object is to provide an improved doubleacting jarringtool for use in a well bore which is lowered and operated in the wellbore on a wire line,

Another object is to provide an improved well jarring tool in which themeans supporting the well jarring tool in a well bore is at leastpartially insulated from the shock of the jars created by the tool.

Another object is to provide an improved Well jarring tool of limitedlength which may be inserted into a well bore and retrieved therefromthrough the usual lubricator.

A further object is to provide an improved well jarring tool which isreleasably held in inactive position until it is positively released todeliver a jar.

These and other objects of the present invention are hereinafter setforth.

The construction designed to carry out the invention will be hereinafterdescribed, together with other features thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and where- FIGURE l is a sectional view ofthe preferred form of CII3,406,770 Patented Oct. 22, 1968 jarring tool of the present inventionwith its component parts in position for lowering into the well bore;

FIGURE 2 is another similar sectional view of the jarring tool of FIGURE1 in position immediately before an upward jar;

FIGURE 3 is a sectional view of a portion of the jarring tool of FIGUREl at the moment of upward impact;

FIGURE 4 is a sectional view of a portion of the jarring tool of FIGURE1 at the moment of downward impact;

FIGURE 5 is a detail sectional view of the adjustable jar assembly;

FIGURE 6 is a cross-sectional view of the jar assembly taken on line 6-6in FIGURE 5;

FIGURE 7 is a side view of the hammer to illustrate the variouspositions of the releasable means for holding the jar of the presentinvention in inactive position; and

FIGURE 8 is a sectional view of a modied form of well jarring device ofthe present invention which is suitable for insertion into a Well borethrough the usual lubricator.

The jarring tool of the present invention is a mechanical jar which, inits preferred form, includes a spring-loaded accelerator to provide thedesired impact force for jarring and to at least partially insulate themeans supporting the jar from the impact forces. The mechanical jarassembly I is provided with a fishing connection F of any suitable typefor engaging a device in a well bore. The jar assembly I is below andconnected to the accelerator assembly A. The weight assembly W isprovided with the usual wire line connection at its upper end andconnects to the accelerator assembly A at its lower end. The jarringtool is lowered into a well bore wit-h the assemblies connected, asshown in FIGURE l, on the wire line 10. The fishing connection F engagesto the device to be jarred before the jarring tool is actuated.

The weight assembly W is sufficiently long to provide the weightnecessary for resetting the jar assembly after it has jarred in anupward direction. The body 12 of weight assembly W is connected to thewire line connection 14 at its upper end and has a sub 16 at its lowerend to engage the stem 18 extending upwardly from the acceleratorassembly A.

The accelerator assembly A provides the storingv of energy for thejarring tool so that when the jar assembly releases, the acceleratorassembly A exerts a force to accelerate the moving components of t-hejar assembly I to impact. The body 20 of accelerator A is tubular inshape with a central bore 22 extending therethrough. Upperv sub 24 issecured into the upper end of body 20 and is provided with a centralbore 26 through which the stem 18 extends. The bore 26 is larger thanstem 18 to allow the stem 18 freedom of sliding movement therein. Thestem 18 is secured to the sub 16 as by threading and extends through thebore 26 into the bore 22, terminating in head 28. The head 28 is smallerin diameter than the bore 22 in body 20 to allow reciprocating movementof head 28 therein. The head 28 is biased downward with respect to thebody 20 by the spring 30 which surrounds stem 18 within body 20. Theupper end of spring 30 abuts the lower surface 32 on upper sub 24 andthe lower end of spring 30 abuts the upper surface 34 on head 28. Inthis way the spring 30, whenever compressed, exerts a downward force onhead 2.8 and an upward force on up` per sub 24. Thus, the spring 30provides a resilient connection between the weight assembly W and thejar assembly I The lower end of body 20 includes the sub 36. The jarassembly I is connected to the accelerator assembly A by the threadedengagement of the sub 38 within the sub 36 and the connecting rod 40engaging in the sub 38.

The function of the jar assembly I is to resist an upward pull by thewire line 10 when it has engaged the device to be jarred and to suddenlyrelease with a rapid movement to cause an impact which is transmitted tosuch device. The body 42 of jar assembly I is tubular and includes acentral bore 44. Rod 40 extends through the upper closure 46 andterminates in the hammer 48 as best seen in FIGURE 5. In runningposition means is provided, such as shear pin 49, to releasably securethe hammer 48 to the body 42 as hereinafter explained with reference toFIGURE 7. Latch body 50 is threaded into the lower end of hammer 48. Theintermediate portion of latch body 50 is cylindrical in shape and isprovided with internal threaded bore 52 to receive adjusting screw 54.The lower end of latch body 50 is divided into a plurality of downwardlyextending arms 56, each of which terminates in outward projections ordogs 58.

Cooperating with the dogs is the inward projection 60 on tubular member62 which is threaded into the lower end of body 42. The upper outerportion of each of the dogs 58 is provided with a steep or sharplytapered surface 64 which engages the sharply tapered surface 66 onprojection 60 when the latch body 50 is raised with respect to jar body42. The lower outer portion of dogs 58 is provided with the graduallytapered surface 68 which cooperates with the upper gradually taperedsurface 70 on projection 60 for resetting the jar assembly J after anupward impact.

The position of the head 72 on adjusting screw 54, the flexibility ofthe arms 56 and the steepness of the tapered surfaces 64 and `66determine the tension needed in wire line 10 to actuate the jar assemblyI to provide an upward jar. This tension in wire line 10 to release thedogs, because of the compression of spring 30 in the acceleratorassembly, is therefore also directly related to the severity of theimpact force produced. The marks 57 on the arms 56 yare used toPreselect the jar force to be developed. Such marks 57 can be seenthrough the window 63 defined by the member 62 and the body 42. Bypositioning the head 72 of adjusting screw 54 with reference to themarks 57, the jar force may be preselected. For example, t-he upper markmay be selected to provide a 10U-pound jar, the intermediate mark a200-pound jar land the lower mark a 300Jpound jar.

The force necessary to shear the pin 49 is always less than the force toactuate the jar. In this manner, the pin 49 holds the jar assembly ininactive position luntil it is ready to exert jarring impacts. The wireline 10 is raised with sufficient tension to create the force necessaryto shear the pin 49.

As seen in FIGURE in dashed lines, the adjusting screw 54 has beenlowered with respect to its solid line position. Since release of thejar assembly J requires that the dogs S8 pass through the restrictedarea defined by the projection 60, the position of head 72 on screw 54varies the amount degree of bending of arms 56 for release. With thehead 72 in its solid line position, the bending necessary for release ofarms 56 takes place over a longer distance than with the head 72 in itslower position. Thus, the lower the head 72 is positioned, the greaterthe force is which is required to pull the dogs 58 through theprojection 60. For this reason, by aligning the head 72 of the adjustingscrew 54 with the marks 57 in the arms 56, the jar force may bepreselected as previously described. The fishing connection F isconnected to the lower end of tubular member 62 so that any jar of thejar assembly J is transmitted to the device which is to receive thejarring impact.

As previously explained, the means releasably holding the jar inactiveincludes the shear pin 49 which extends through one of the holes in thebody 42 `and the hammer 48. As best seen in FIGURE 7, a pluarlity ofholes of different sizes extend through body 42 and hammer 48 to receivethe pin 49 which has been preselected to determine the force needed toactivate the jar assembly. The smaller the pin the smaller the forceneeded to shear it and activate the jar.

In operation, the jarring tool is run into a well bore in the positionas shown in FIGURE l. When the fishing tool F has engaged the device tobe jarred, the wire line is lifted. Lifting of the wire line raises theweight assembly W, the rod 18 and the head 28 on rod 18 to initiallyshear the pin 49 Iand thereafter to compress the spring 30. The jarassembly J and the body of the accelerator assembly A are not movedinitially.

FIGURE 2 illustrates the position of the jarring tool as the dogs 58start their upward movement. In this position, the spring is compressedto exert an upward force on accelerator body 20 and on rod 40. When thedogs 58 are above the projection 60, the rod and hammer 48v areacceleratedin an upward direction bythe force of spring 30. The jarringimpact occurs when hammer 48 hits upper closure 46. This moment ofimpact is illustrated in FIGURE 3. This impact is transmitted fromclosure 46 through jar body 42, tubular member 62 and fishing connectionF to the device to be jarred.

Resetting of the jarring tool is accomplished by lowering wire line 10until the dogs 58 are forced downwardly through the interior ofprojection 60. The tapers on surfaces 68 and 70 on the projection 60 anddogs 58 are sufciently gradual to allow the weight of the tool above toaccomplish the resetting. With the dogs 58 below the projection 60, thetool is then ready to deliver another im# pact.

A downward impact may be delivered by lifting the wire line 10 with aforce less than the force required to release the jar assembly I and,thereafter, releasing all tension on the wire line 10. Before the wireline 10 is released, the spring 30 is under almost as much compressionas during release for upward jar. When the wire line 10 is released, thespring force is exerted to accelerate the downward movement of head 28and weight assembly W. This downward movement is transferred by impactof the weight assembly W on accelerator body 20 which hits upper closure46 of the jar assembly J with a downward impact. This downward impact istransmitted through the tubular member 62 and the fishing connection Fto the member being jarred. The downward impact between acceleratorassembly A and jar assembly J is shown in FIGURE 4. When a downward jaris applied by the jarring tool, no resetting of the jar assembly J isrequired since the dogs 58 remain below the projection at all timesduring a downward jar.

The accelerator assembly A, in addition to preserving the energy for thejars, insulates the wire line 10 from the shocks of the impacts sincethe spring 30 forms a part of the connection between the jar assembly Jand the wire line 10.

In certain applications on well bores, it is desirable that the lengthof the well jarring tool be short to allow the whole assembly to beinserted into the well bore through the usual lubricator. In suchapplications, the modified form of the present invention illustrated inFIG- URE 8 is used. This well jarring tool is the same as the preferredform of well jarring tool previously described except that it does notinclude the accelerator assembly A. This modified tool includes a weightassembly W-l supported on a wire line by the wire line connection 82,the jar assembly I-l and the fishing connection F-l.

The weight assembly W-l is sufficiently long to provide the weightnecessary for resetting the jar assembly after it has been jarred in anupward direction. The body 84 of the weight assembly W-1 is connected tothe wire line connection 82 at its upper end and has a sub 86 at itslower end to engage the rod 88 extending upwardly from the jar assemblyJ-l.

The function of the jar assembly J-l is to resist an upward pull by thewire line 80 when the fishing connection F-l has engaged the device tobe jarred and to suddenly release with a rapid movement to cause animpact which is transmitted to such device. The body 90'of the jarassembly J-l is tubular and includes a central bore 92. Rod 88 extendsthrough the upper closure 94 and terminates in the hammer 96 as shown inFIGURE 8. In running position, means li`s provided, such as shear pin98, to releasably secure hammer96 to the body 90 as hereinafterexplained.v Latch body 100 is threaded into the lower end of' hammer'96.The intermediate portion of latch body 100 is cylindrical in shape andis provided with internal threaded bore'to receive an 'adjusting `screw(not shown) as hereinbefore described with respect to the jar assembly Jof FIGURE 1. The lower end of latch body 100 is divided into a pluralityof downwardly extending arms 102, each of which terminates in outwardprojections or dogs4. The inner projection 106 of body 90 functions tohold the dogs 104 until a preselected upward force has been applied;`The construction of theremainder of the ja'r assembly 1*1 isidentical'to the'construction of the jar assembly I aspreviouslydes'cribed with respect to FIGURE 1. The releasable holdingmeans, the shear pin 98 and the provision for insertion ofdifferent-size shear pins through the body 90 and the hammer 96 is alsoidentical in structure andoperation to that previously described withrespect to the jar assembly J.

"From 'FIGURE 8 and the foregoing description, it can beseen that thewelljarringj tool of rthemodifiedform shown and described omits theaccelerator assembly and, therefore, is sufficiently short in length toallow it to be installedinto a well bore through the usual lubricator.

In operation, the modified form of the well jarring assembly providesboth an upward and a downward jar. Since the accelerator assembly hasbeen omitted, the length of the wire line 80 should have suicientelongation to maintain the upward velocity of the hammer 96 once thedogs 1,04 have passed through the inner projection 106. When it isplaced under the tension sutlicient to actuate the well jarringassembly, the wire line 80 has a certain amount of elongation withoutany permanent deformation; and when the dogs release the jar assemblybefore jarring, the tension in the wire line exerts an upward force tomove the weight assembly W-l and the hammer 96 upwardly until the hammerreaches and impacts against the upper colsure 94 of the jar assembly J-LFollowing an upward jar, the jar assembly J-1 is readily reset byreleasing the tension on the wire line 80 allowing the whole weight ofthe weight assembly W-1 to force the rod 88, the hammer 96 and the latchybody 100, including the arms 102 and the dogs 104,- downwardly untilthe dogs 104 pass through the inward projection 106. Impact between thesub 86 of the weight assembly W-l and the upper closure 94 of the jarassembly J-1 on resetting creates a downward jar which is transmittedthrough the body 90 and the fishing connection F-1 to the device whichis stuck in the well.

The modified form of well jarring tool of fthe present invention can berun into a well bore through the usual lubricator and, in most cases,has a sufficiently short length to allow the jar to be run connected towell swabs. The shear pin 98 holds the jar in an inactive positionunxtil such time as it is connected to the device which is to receive animpact jar. At that time, lifting of the wire line creates sufficientforce to shear the lshear pins activating the jar and thereafterproviding a jar whenever sufficient Iadditional upward force is exertedon the wire line 80 to cause the dogs 104 to pass through the inwardprojection 106 in the body of the jar assembly.

From the foregoing it can be seen Athat the jarring tool of the presentinvention may readily be operated by wire line from the surface of awell bore to provide jarring impacts to a member in the well bore. Theseimpacts may be imparted either upward or downward in any desiredsequence and the jarring tool further has provision for preselecting theimpact force before the jarring tool is run. Also, the modied form ofthe well jarring tool of the present invention can be used inapplications where the tool is to be inserted into a well bore throughthe usual lubricator.

In both forms of the invention illustrated, the means holding the welljar assembly in an inactive position-that is, the shear pi-nsrestraining movement'of the hammer with respect to the bodyassures thatthe jar is not actuated until suiiicient force has been exerted on thewire line to shear the pins.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, Iand various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What is claimed is:

1. A rwell tool adapted to impart jarring impacts to a device within awell bore, comprising:

a mechanical jar including a tubular body, an inward projection |withinsaid body, a latch body having arms extending through said projectionand each arm ter- I minating in an outwardly extending dog, saidprojection and said dogs having sharply tapered mating surfaces for theactuation of said jar in one direction and gradually taperedmatingsurf-aces for the resetf ting of said jar after' actuation in saidone direction,

means connecting to said mechanical jar and adapted -to engage a devicewithin the well bore to be jarred,

means adjusting said mechanical jar including an adjusting screw inthreaded engagement fwitlh said latch body and having a head surroundedby said arms, the position of said head determining the force necessaryto actuate said jar in said one direct-ion,

releasable means holding said jar in inactive position,

a weight assembly connected to said jar, and

means connecting said weight assembly to the surface whereby the liftingof said connecting means imposes a load on said jar which is preselectedto release said releasable engaging means and thereafter to exceed thepreselected force necessary to actu-ate said jar.

2. A well tool according to claim 1, including:

means indicating the jar force in relation to the position of saidadjusting screw.

3. A well tool according to claim 2, wherein said indicating meansincludes:

a window defined by and extending lengthwise of said body from the upperto the lower position of one end of said adjusting screw, and

indicia on one of said arms marking at least two position's to locatesaid end of said adjusting screw with reference to said indicia and tothereby preselect lthe force of impact of said mechanical jar.

4. A well tool adapted to impart jarring impacts to ya device within awell bore, comprising:

a mechanical jar including a tubular body, an inward projection withinsaid body, a latch body having arms extending through said projection'and each arm terminating in an outwardly extending dog,

said projection and said dogs having sharply tapered mating surfaces forthe actuation of the jar in one direction and gradually tapered matingsurfaces for the resetting of the jar after actuation in said onedirection,

means on said jar for engaging a device within the well bore to bejarred,

a spring-loaded accelerator connected to said jar to impose a load onsaid jar when said accelerator is lifted,

means connecting from said spring-loaded accelerator to the surface,

the lifting of said connecting means lifting said accelerator to imposea load on said jar which is predetermined to exceed the force to actuatethe jar in one `direction and to impose a load on said jar which ispredetermined to be less than the force .to actuate said jar in theopposite direction upon release of said connecting means,

an adjusting screw in threaded engagement with said latch body and[having a head surrounded by said arms, the position of `said headdetermining the force necessary to actuate said jar in said direction,and

said accelerator being adapted to accumulate the lifting force of theaccelerator connecting means and to transmit said force to said latchbody whereby when the preset actuating force is exceeded, said arms passthrough said projection and said latch body impacts against said tubularbody.

S. A well tool adapted to impart jarring impacts to a device within awell bore, comprising:

a mechanical jar including a tubular body having an rupper closure andan inward projection wiltxhin said body and a latch body having armsextending through said projection,

means coacting with said arms to preselect the force necessary to pullsaid arms through said projection,

'a rod extending through said closure `and a hammer within said tubularbody and adapted .to engage said upper closure to impart upward impactsthereto,

a spring-loaded accelerator connected to said rod,

first means for connecting from said spring-loaded accelerator to thesurface of the well bore in which said jar and accelerator arepositioned,

second means for connecting from said tubular body to a device stuck inthe well bore whereby impacts on said closure are transmitted to saiddevice,

said accelerator having a sub adapted to engage said upper closure toimpart downward impacts thereto,

said accelerator being adapted to accumulate the lifting force of saidfirst connecting means and to transmit said force to said rod wherebywhen said preselected force is exceeded, said arms of said latch bodypass connecting means comprises a lwire line connecting to said welltool.

8. A well tool according toclaim S, wherein:

the spring of said accelerator is compressed during loading of saidmechanical jar and upon release exerts a force to increase the -impactforce.

References Cited UNITED STATES PATENTS 1,848,535 3/1932 McCullough175--302 1,989,907 2/1935 Beck 175-304 X 2,143,349 1/1939 Hobbsv175---302 2,144,869 1/1939 Boulter 175--299 2,241,477 5/ 1941 Rasmussen175-302 2,671,640 3/ 1954 Baker 175-299 2,733,046 1/ 1956 Thompson175-304 X 2,876,993 3/1959 Hooks 175-301 3,203,482 8/1965 Lyles 175--299DAVID H. BROWN, Primary Examiner.

